[Tree] baekjoon-11725

Author: Seogeurim

README.md

@@ -165,6 +165,7 @@
 | 03  |     | [SWEA-1233 사칙연산 유효성 검사](./src/Tree/swea1233) |      |
 | 04  | ⭐️ | [Baekjoon-1167 트리의 지름](./src/Tree/P1167)   |      |
 | 05  | ⭐️ | [Baekjoon-2263 트리의 순회](./src/Tree/P2263)   |      |
+| 06  |     | [Baekjoon-11725 트리의 부모 찾기](./src/Tree/P11725) |      |
 
 ### Heap
 

src/Tree/P11725/Main.java

@@ -0,0 +1,44 @@
+package Tree.P11725;
+
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    static int N;
+    static int[] parents;
+    static ArrayList<Integer>[] edges;
+
+    public static void main(String[] args) throws Exception {
+        System.setIn(new FileInputStream("src/Tree/P11725/input.txt"));
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+        N = Integer.parseInt(br.readLine());
+
+        parents = new int[N+1];
+        edges = new ArrayList[N+1];
+        for (int i = 1; i <= N; i++) edges[i] = new ArrayList<>();
+
+        for (int i = 0; i < N-1; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            int a = Integer.parseInt(st.nextToken()), b = Integer.parseInt(st.nextToken());
+            edges[a].add(b);
+            edges[b].add(a);
+        }
+
+        Queue<Integer> q = new LinkedList<>();
+        q.offer(1);
+        while (!q.isEmpty()) {
+            int cur = q.poll();
+            for (int e : edges[cur]) {
+                if (parents[e] > 0) continue;
+                parents[e] = cur;
+                q.offer(e);
+            }
+        }
+
+        StringBuilder sb = new StringBuilder();
+        for (int i = 2; i <= N; i++) sb.append(parents[i]).append("\n");
+        System.out.println(sb.toString());
+    }
+}

src/Tree/P11725/README.md

@@ -0,0 +1,5 @@
+## [baekjoon-11725] 트리의 부모 찾기
+
+![image](https://user-images.githubusercontent.com/22045163/108373876-b6ca0400-7243-11eb-9cc2-f36377d877aa.png)
+
+![image](https://user-images.githubusercontent.com/22045163/108373917-bfbad580-7243-11eb-898b-72bfee6cab19.png)

src/Tree/P11725/input.txt

@@ -0,0 +1,7 @@
+7
+1 6
+6 3
+3 5
+4 1
+2 4
+4 7